On 7/1/2013 5:05 PM, LuKreme wrote:
> On 30 Jun 2013, at 06:05 , Wietse Venema <wietse@...> wrote:
>>> When reject_unknown_client_hostname triggers on an NXDOMAIN it
>>> returns a 550 error, which is great. When it triggers because there
>>> is no PTR record, it returns a 450 error, which is also great?
>> That is incorrect. The 450 code is for errors where lookup
>> failed (no result instead of "does not exist").
> Does not exist is NXDOMAIN, right?
> When the result is empty, like in this recent spammer:
> $ dig -x 18.104.22.168 | grep -A1 ";; Q"
> ;; QUESTION SECTION:
> ;22.214.171.124.in-addr.arpa. IN PTR
> postfix returns a 450. (Note, I'm not complaining about postfix's behavior)
> This IP has been failing with a 450 for weeks, but there are many.